Issues contouring iso-surfaces with with different variable
 

I am trying to create isosurfaces of Q-criterion that are flood contoured by eddy viscosity. The issue is that usually, when I choose eddy viscosity as the flood variable in the Contour and Shade tab, it automatically changes the iso-surfaces to eddy viscosity too. Note - I have to go into the Contour & Multi-Coloring Details tab to access either of these variables. I've gotten it to stick, but seemingly just by trying this a bunch of times. Is there a sure-fire way I can make this work?

Another note - when I select one of the readily available variables from the "Flood by" drop down (ex. static entropy, shear strain rate, etc.) I have no issues. Is there a way I can ensure eddy viscosity will be in this list?

Thanks!

Tecplot uses the concept of "Contour Groups" which are a mapping between a variable and how they are drawn. There are 8 contour groups and they are defined in the "Contour groups and multi coloring details" dialog which is what launches when you click the details button on the sidebar next to contour as well as the gear icon in the isosurface dialog. They were implemented this way to allow users quickly change multiple areas of their plot at the same time, but it can cause confusion.

For legacy reasons, isosurfaces are defined by Contour Groups rather than defining the variable itself. All contour coloring throughout also go through Contour Groups.

In your case you have to ensure that your isosurface is defined by contour group #1 (the 1 button at the top of Contour and Multi Coloring dialog) which is associated with Q-Criterion while selecting contour group #2 (the 2 button) which you can define as eddy viscosity and use that to flood your isosurface by.

Other places you can see the 1-8 contour groups are the context menu as well at the bottom of the color selector where the first button says Multi 1, those buttons assign the color to be the first 8 contour groups.

Ah, that makes sense. Thanks, your advice worked perfectly.